This invention relates to a universal rolling mill having a set of both horizontal and vertical rolls for rolling structural sections, beams, rails, and other shaped products. More particularly, it relates to an internal frame construction mounted in the mill for carrying the vertical rolls and in which the horizontal rolls are mounted and which frame remains in the mill during roll set changing and is moved vertically with the vertical and horizontal rolls for pass line adjustment for varying size stock. A removable part of the frame and an automatic stooling pin arrangement interlocking the chocks for both the vertical and horizontal rolls facilitate roll set changing.
When rolling beams or similar shaped sections in a universal rolling mill, so-called lifting or tilting tables are usually employed to convey the stock traveling on the entry and delivery roller tables to and from the rolling mill. Lifting tables are essential because on the one hand, the level of the transporting surface of the approach table is otherwise fixed and, on the other hand, the height of the pass line will be determined and fixed in relation to the surface of the roller table by the largest shape to be rolled. When smaller sections are to be rolled in the mill, it is thus necessary to accommodate the difference in the height of the roller table surface and the pass line by means of lifting tables to ensure that the section enters and leaves the universal mill at the proper roll pass elevation.
Through the use of lifting tables, the shape to be rolled is advanced into the mill essentially at an angle to the pass line. This in many cases can create unacceptable product due to the undesirable stresses and deflection of the product during rolling.
To some extent this problem is exemplified in U.S. Pat. No. 3,968,672 issuing on July 13, 1976. These lifting tables are used with the stands where the vertical and horizontal rolls are fixed, i.e., the pass line cannot be varied due to the mounting of the vertical rolls in the mill.
An arrangement had been devised where a cassette frame carrying both horizontal and vertical rolls is supported on a traversable carriage in the vertical housing windows. This type of cassette frame construction allows for passline adjustment and is accomplished by providing shims, threaded spindles, wedges, or piston cylinder assemblies arranged between the frame and carriage. A mill with a cassette frame is exemplified in U.S. Pat. No. 3,559,440 issuing Feb. 2, 1971.
A serious limitation to this cassette type frame is that the frame is joined together and the roll set is an integral part of the cassette frame. When it is necessary to change the roll set, there is no easy way for the cassette frame to remain in the mill, and still gain access to the roll set. The cassette frame with its roll set must be removed from the mill and replaced by another cassette frame with its roll set. In order to replace the worn roll set, the cassette frame has to be conveyed to a working area for its disassemblage and reassemblage. This operation requires added expense represented in labor, time, and equipment. The overall effect of these immediately aforesaid economic factors reduces considerably the significance of the advantage realized from the use of the cassette frame of the present day designs.
The aforesaid drawbacks when using lifting tables for rolling beams and other shaped sections with universal mills are eliminated with the teachings of the present invention. A mill is thus provided which enables the oncoming and exiting stock to be conveyed from the approach and delay tables respectively relative to the mill passline without the need of a lifting table.
The aforesaid drawbacks when using the integral cassette frame which must be removed with the roll set are also eliminated with the teachings of the present invention. A mill is thus provided which supports a frame for carrying the roll set which frame remains in the mill and only a portion of the frame on the operating side of the mill is quickly made removeable so that the roll set can be removed in a roll set changing operation.